Nutrition · Moderate evidence
Weight change is dynamic
The body's weight response to sustained changes in energy intake is gradual and involves adaptations; projections should use curves and ranges rather than a rigid linear rule.
Mathematical model validated in controlled feeding studies · 3 sources · 2 min
What the studies show
- The 3500 kcal per half-kilogram rule overestimates weight loss because it ignores the drop in energy expenditure as body weight decreases.
- Weight loss slows down over time even with the same calorie deficit.
- Validated dynamic models describe the weight trajectory far better than linear calculations.
How Letz applies it
The weight forecast in Progress uses the observed trend and an uncertainty range, never a promised target date.
Numbers derived from this rule
| Parameter | Range | Weight | Rule |
|---|---|---|---|
| Calorie deficit | 10–25 % of expenditure1 variant by context | 80% | Deficit of 10 to 25% of expenditure, aiming for a loss of 0.5 to 1% of body weight per week; faster rates cost lean mass and metabolism.Rate of weight loss · Higher Protein Intake During a Calorie Deficit · Weight change is dynamic |
Who it applies to
Non-pregnant, non-lactating adults, for educational and planning support.
Limits
A population model does not precisely predict an individual's response; incomplete logging and behavioral changes increase uncertainty.
Sources
- Hall et al., The Lancet, 2011 DOI 10.1016/S0140-6736(11)60812-X
- NIDDK Body Weight Planner — pesquisa e validação
- Thomas et al., International Journal of Obesity, 2013 DOI 10.1038/ijo.2013.51
More in Nutrition
- Protein and Training AdaptationSufficient protein can support gains in lean mass and strength alongside training; the response varies and does not increase indefinitely with higher intakes.
- Higher Protein Intake During a Calorie DeficitIn a deficit, higher protein protects lean mass and can even allow muscle gain alongside intense training; the effective range rises to approximately 1.6 to 2.4 g/kg.
- Rate of weight lossLosing weight slowly, at around 0.5 to 1% of body weight per week, better preserves lean mass, strength, and metabolic rate compared to rapid weight loss.
- Distribute protein throughout the dayDividing protein into servings of around 0.4 g/kg across four or more meals stimulates protein synthesis more than concentrating everything into one or two.